'''Lettuce''' (''Lactuca sativa'') is an annual plant
of the daisy family Asteraceae
. It is most often grown as a leaf vegetable
, but sometimes for its stem and seeds. Lettuce was first cultivated by the ancient Egyptians
who turned it from a weed
, whose seeds were used to produce oil, into a food plant grown for its succulent leaves, in addition to its oil-rich seeds. Lettuce spread to the Greeks and Romans, the latter of whom gave it the name '''', from which the English ''lettuce'' is ultimately derived. By 50 AD, multiple types were described, and lettuce appeared often in medieval writings, including several herbal
s. The 16th through 18th centuries saw the development of many variety (botany)|varieties
in Europe, and by the mid-18th century cultivars were described that can still be found in gardens. Europe and North America originally dominated the market for lettuce, but by the late 20th century the consumption of lettuce had...